Interposer for semiconductor, method for manufacturing the same and semiconductor device using such interposer

Abstract

An interposer adapted to be used between a mounting board and a semiconductor chip which is to be mounted on the mounting board. The interposer having a heat-resistant insulator having first and second surfaces, the insulator being provided with a plurality of through-holes opened at the first and second surfaces; wiring patterns formed on the first and second surfaces of the insulator electrically connected to each other by means of a conductor provided on an inner wall of at least one of the through-holes; and a capacitor. The capacitor has first electrode formed on the insulator and having a connecting portion formed on an inner wall of at least one of the other through-holes, a dielectric layer formed on the first electrode, and a second electrode formed on the dielectric layer.

What is claimed is:  
     
       1. An interposer adapted to be used between a mounting board and a semiconductor chip which is to be mounted on the mounting board, the interposer comprising: 
       a heat-resistant insulator having first and second surfaces, the insulator being provided with a plurality of through-holes opened at the first and second surfaces;  
       wiring patterns formed on the first and second surfaces of the insulator electrically connected to each other by means of a conductor provided on an inner wall of at least one of the through-holes; and  
       a capacitor comprising a first electrode formed on the insulator and having a connecting portion formed on an inner wall of at least one of the other through-holes, a dielectric layer formed on the first electrode, and a second electrode formed on the dielectric layer.  
     
     
       2. An interposer as set forth in  claim 1 , wherein the capacitor is arranged on the insulator and in a vacant area between the wiring patterns. 
     
     
       3. An interposer as set forth in  claim 1  further comprising connecting bumps on the wiring patterns and on the second electrode, the connecting bumps being used for electrically connecting the interposer to the mounting board. 
     
     
       4. An interposer as set forth in  claim 1 , wherein the insulator is made of silicon. 
     
     
       5. An interposer as set forth in  claim 1 , wherein the insulator is made of glass. 
     
     
       6. An interposer as set forth in  claim 1 , wherein the insulator is made of a heat-resistant polyimide. 
     
     
       7. An interposer as set forth in  claim 1 , wherein the capacitor comprises the first electrode formed on at least one of the first and second surfaces of the insulator, and the dielectric layer formed on the first electrode and the second electrode formed on the dielectric layer. 
     
     
       8. An interposer as set forth in  claim 1 , wherein the capacitor comprises the first electrode, at least a part thereof being formed on the inner wall of the through-hole, the dielectric layer formed on the first electrode and the second electrode formed the dielectric layer. 
     
     
       9. A method of manufacturing an interposer adapted to be used between a mounting board and a semiconductor chip which is to be mounted on the mounting board, the method comprising: 
       a step for forming a plurality of through-holes to a heat-resistant insulator having first and second surfaces, so that the through-holes are opened at the first and second surfaces;  
       a step for forming a first conductor layer on the first and second surfaces and inner walls of the through holes of the insulator;  
       a step for patterning the first conductor layer to form wiring patterns on the first and second surfaces of the insulator electrically connected to each other by means of the first conductor provided on the inner wall of at least one of the through-holes and to form a first electrode on the insulator so that the first electrode is electrically connected to the first conductor formed on the inner wall of at least one of the other through-holes;  
       a step for forming a dielectric layer to cover the first electrode and the wiring pattern;  
       a step for patterning the dielectric layer to form the dielectric layer on the first electrode;  
       a step for forming a second conductor layer on the insulator to cover the dielectric layer;  
       a step for patterning the second conductor layer to form a second electrode on the dielectric layer.  
     
     
       10. A method as set forth in  claim 9 , the method further comprising a step of forming connecting bumps on the wiring patterns and the second electrode. 
     
     
       11. A semiconductor device comprising: 
       a mounting board;  
       a semiconductor chip mounted on the mounting board by means of an interposer disposed therebetween, so that predetermined portions of the semiconductor chip are electrically connected to the mounting board through the interposer, the interposer comprising:  
       a heat-resistant insulator having first and second surfaces, the insulator being provided with a plurality of through-holes opened at the first and second surfaces;  
       wiring patterns formed on the first and second surfaces of the insulator electrically connected to each other by means of a conductor provided on an inner wall of at least one of the through-holes; and  
       a capacitor comprising a first electrode formed on the insulator and having a connecting portion formed on an inner wall of at least one of the other through-holes, a dielectric layer formed on the first electrode, and a second electrode formed on the dielectric layer.